345-MW/cm² 2608-V NO₂ p-Type Doped Diamond MOSFETs With an Al₂O₃ Passivation Overlayer on Heteroepitaxial Diamond

Diamond metal oxide semiconductor field effect transistors (MOSFETs) on high-quality heteroepitaxial diamond (Kenzan diamond
^®
) with NO
₂
p-type doping and an Al
₂
O
₃
passivation overlayer exhibited a high off-state breakdown voltage of −2608 V. The 100-nm-thick Al
₂
O
₃
passivation overlayer on the hole channel increased the high-voltage-handling capability of the MOSFETs by substantially suppressing the off-state drain leakage currents. The MOSFET showed a specific on-resistance of 19.74
$\text{m}\Omega \cdot $
cm
²
and a maximum drain current density of −288 mA/mm, with an extremely low gate leakage current
$ < 10^{-{6}}$
mA/mm. The Baliga’s Figure-Of-Merits was experimentally determined to be 344.6 MW/cm
²
, and the maximum DC power density was observed to be 21.0 W/mm.